May 16 2011

Another Cure for Cancer?

In the last week I have received a flood of e-mails asking my opinion about an article, “Scientists cure cancer, but no one takes notice.”  The sensational theme is a familiar one – scientists hit upon a cure for cancer, but since the drug in question is already off patent (or is “natural”) the pharmaceutical industry is not interested in developing it. The more conspiracy-minded take it a step further and declare that “Big Pharma” will keep anyone else from developing it either.

Most of those e-mailing me saw the skeptical red flags in this story, but still many found the idea intriguing. Like most urban legends – something about the story resonates with our hopes and/or fears. The story rides this emotional wave, now supercharged by social media.

In fact, this is an old story about DCA (which I will get into below). The article that has been going around is four years old – there is no date on the article itself, but I recognize the story from several years ago (it has made the rounds numerous times) and there are four-year-old comments on the article. But, someone posted the article on their Facebook page, and someone else tweeted it, and it was retweeted and linked to by other Facebook pages and voila – the magic of the internet has breathed life into a dessicated urban legend.

The Cure for Cancer

This story is a variation on the notion that “they have cured cancer” but the cure is being kept from the masses by greedy interests aided by the lazy and apathetic. This is a topic I have written about before at length. It has a certain psychological appeal (to that little conspiracy theorist inside each of us). There is something compelling about the notion that the powers that be are not acting in our interest. It gives us a (usually false) sense of empowerment to think we are peeking behind the curtain and seeing what’s really going on.

But on close inspection the story makes no sense. The core flaw in this notion is the unstated premise that the medical establishment is a monolithic entity capable of acting with one intent. Rather, like many aspects of our civilization, modern medicine is a complex organism with many independent parts, and no one piece has dominion over all the others. The pharmaceutical industry does not control all of medical research. It does fund a great deal of research, because it has billions of dollars to invest in R&D and it does direct its research funds to developing drugs that will make them money. But there is also billions of dollars in research funding from the government, and from private organizations, patient groups, and other sources. And of course, there are many other countries each with their own medical research infrastructure.

And research is not the only piece of the puzzle either. There are professional organizations, academic institutions, and disease advocacy groups.

The notion of “a cure for cancer” is also highly improbable. Cancer is not a single disease, but a category of disease with a great deal of variation. That is why there are numerous treatments for cancer, and treatments need to be specifically tailored to the cancer type, stage, and location, as well as the individual patient.

DCA Again

But what about this specific treatment – dichloroacetate, or DCA? Promoters of science-based medicine deal with many types of health claims. Some are purely magical, others are physical but are clear quackery. DCA is neither. It is a legitimate drug with an interesting mechanism of action and some potential as a treatment for some cancers and other conditions as well (but to be clear up front, it is not a proven and accepted treatment for cancer in humans).

DCA falls under the category of prematurely promoting an experimental drug before it has been adequately studied. It can sound very compelling to hear the story of how DCA works to kill cancer cells. It certainly sounds like it is a cure for cancer. But medical researchers have been here before. Many potential treatments look good in the test tube, but do not eventually work as treatments in humans. Cancer is complex, and biology is complex, and in a living person the net effects may not be what we expect.

There is also safety to consider. Medical decision-making is about risk vs benefit. There is a tendency for naive and sensational reports to hype a treatment by focusing entirely on the potential benefits. But before we can reasonably recommend or give a treatment, we need to know something about the risks as well. We want to make sure we are not doing more harm than good (I remember something about that in that oath I took when I graduated medical school).

That is why we need to perform those pesky controlled clinical trials. We need some reasonable measure of net clinical effects. The history of medicine has demonstrated this a thousand times over.

Orac has written a thorough series of articles on DCA. Here is the latest, which also contains links to his entire series of articles on the topic. In summary, some cancers survive by switching from burning oxygen to get their energy to deriving energy from anaerobic glycolysis. DCA forces the mitochondria in cancer cells back into their oxygen-burning state which triggers cell death. Again – sounds great in principle. This is a very interesting potential mechanism for attacking cancer, and there is solid basic science behind it.

But again – we cannot leap from compelling basic science to clinical claims. We need to do the actual research, and clinical research proceeds in stages. The reason for this is to sort through the hundreds of interesting potential treatments to see which ones are reasonably safe and promising. Then we proceed to larger and more elaborate trials, and if drugs still appear to be safe and effective then we go on to definitive trials. And then even after that we need to do further study and monitoring to see that the effect of a treatment in the real world is working out. Each step exposes more people to the treatment, and so more and more subtle risks and effects can be detected.

It’s a messy and frustratingly slow process, but the alternative is to be buried in potential treatments, most of which will be useless or harmful. Without this research process we would be doing more harm than good. It’s like going bankrupt playing the lottery, hoping to score big, when instead you should be making sound long-term investments.

Right now the preliminary evidence for DCA is weak but there is still a glimmer of promise. It looks like the cytotoxic potential (ability to kill cancer cells) is low, and therefore any clinical effect may be limited. Further, serious side effects are also coming to light. The drug has been linked to serious encephalopathy (brain dysfunction) and neuropathy (nerve damage).

Meanwhile researchers are experimenting with chemical variants of DCA that may have higher anti-tumor activity and less toxicity.

What all of this research also shows is that – DCA is being researched. Contrary to the core claim in the article making the rounds, DCA is getting just the research attention it deserves.


DCA is just one of many potential future cancer treatments in the pipeline. It is an interesting approach, focusing on cancer cell metabolism, specifically mitochondrial function, and that may be the most interesting thing about DCA. But in its current form its activity seems to be low and its toxicity high. It may still find a role in cancer treatment. There may be specific cancers for which it has high activity, especially when combined with other treatments. There is a lot of research to be done. And we may find derivatives that are even better. Or, it may ultimately fail as a treatment.

A common story in the cancer-treatment world is that a new potential treatment, based upon a novel approach, is sensationalized as a cure for cancer. But then 5-10 years later we still haven’t cured cancer. But what has often happened is that the new treatment works, it just has a limited role in a subset of cancers. It prolongs survival and is being used – it’s just not the “cure” that it was originally hyped to be.

The history of cancer treatment has taught researchers to be humble and realistic. New treatments are great, and they are each contributing to the slowly increasing survival of many cancers. We are making progress with a lot of singles – just not the grand-slam home-runs that the media wants for good headlines.

So don’t believe the conspiracy-mongering and the hype. The research is happening. It is being targeted largely to therapies in proportion to their promise. But unfortunately research progresses much more slowly than rumors spread through Facebook and Twitter.

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